Acts is really a continuation of Luke, so it makes sense to take a running start by reviewing the last chapter of Luke before diving into Acts 1. Go ahead, I'll wait.
In verses 1-10 you can see immediately the parallel with Mark 16. There are differences, too. Mark reports that the women were scared and didn't tell anyone, while Luke reconts that they told the disciples. Luke lists Mary Magdelene, Mary the mother of James, Joanna, and some others. Mark lists the two Marys and Salome. Luke says they saw two men. Mark says they saw one man sitting on the right side. There's also Matthew's version and John's version.
Skeptics love to crow about these differences as "contradictions." How can all these different accounts possibly be true? You can decide for yourself. Read carefully and you'll see that John's account is the only one that's really divergent, but they're not mutually exclusive.
I'll save the details for Easter, though. :-) For now, lets continue on into Acts.
In Acts 1, Jesus tells the disciples to wait in Jerusalem until he sends the Holy Spirit. The disciples choose Matthias to replace Judas. He's not elected, but chosen by lot - to the Jews, a sacred method of making decisions.
In Acts 2, the Holy Spirit descends as tongues of flame, and the apostles preach in the languages of their audience. Were they empowered to speak, or were the listeners empowered to hear? Doesn't matter. The Word gets out, and a community of believers begins to form.
In Acts 3, Peter heals a man unable to walk. The telling thing is that he does so not by his own power, but by the power of faith in the name of Jesus. Surely the lame man had been present a few weeks before when Jesus had cleared the merchants and moneychangers out of the courtyard. He may have heard the cries of "Give us Barabbas!" and "Crucify him!" echoing through the streets. And he may well have heard the strange whispers beginning to circulate that Jesus had been seen alive again.